Inclinometer



p 1949- T. D. PENNINGTON 2,482,504

INCLINOMETER Filed Aug. 12, 1946 2 Shee'ts-Sheet 1 I IN V EN TOR- T/ 2. Pennznyon Sept. 20, 1949- D. PENNINGTON INCLINOMETER Filed Aug. 12, 1946 2 Sheets-Sheet 2 4 m N n E0 Dy SB 4 m 0 Patented Sept. 20, 1949 or srcs 7 mcnmormrnn; aims n.1Pennmgton-,;Brmem-, Ni J1; Application August 12, 1a4s,.seria1.No..ss9,919-

aim or this intention- 1s to a novel inclinometer for use 'upon aircrait; designed to indicatethrough 36(i degrees;either the lateral car longitudinaltiltihrgrei sadi aircm fts-or any eombinationof snchziateral and longitudinal tilting. s

The means-by which Icawomplishmeaforeeoing. object and the many advantages flowing therefrom will he. inset-understood .by reference to the accompanying drawings. wherein:;

r 4;:eui'ms. (cr es-4159 Figure,.-.1. isv a view. partly longitndineiseetionand partlywiniside eievationnizaadnclinometer constructed in accordance with theinvcntion; l,

Figure 2,is a: front elevation .ofjs'thesame; 7 Figures is a face view ofvan electrieom'ren distributor hereinafter described;

Figure. 4 is a traamentarysectioneih View 7 through the distributor Figure 5 is a vertical sectional viewe-u 5.-5. of. Figure 1, through a .tactnaking structure hereinafter described; Figure '6..'is.a .sectionalfxfiew throu ghihe structure of Figure 5,'a't 'rightanslesltd-theshowing of Figure 5; and.

Figure 7 is a diagrammatic. viewIofthewirling employed;

In the particular form of invention I have. chosen for purposes of illustration, f5i' desig'rlates a base" of woodfor other 'nonecondnctive material thatis adapted to be secured'tothe instrum'ent board of an airplane in front ofthe pilot. A bracket 6' supports a rodorfshaff'll VA sleeve Bis mounted upon 'said' shaft. preferably by-anti-friction bearings 9; vAtits forward end this sleeve carries a dial disk .lll that'is graduated in each direction *throughiBU from'its zero point H. The forward :end' of the rod"! carries a pointer 12. This pointer coacts with the scale constituted by the g'raduati'ons upon-the disk.

Depending from and rigidiyaffixedtd sleeve "8 is a hanger 13; which with'tl're parts mounted thereon constitutes a pendulum; which pendulum tends to hold the gradnated'disk lfl ma fixed position: 'ihepointer i z-"nrcvesovertire graduateddisk; eitherto ieftofits-"zero point under the -l-at-eral tilt of plane'- as it banks eithertorie'ht-or-left;

Te indicate the fore anaiart tiiting effthe plane I mount in the'lower end of hanger Ha drum 14'; This drum carries a weight lFi 'at' its lower portion. Thus the drum constitutes a-seoonfl pendulum thatfi's 'carri-edibodiiy bythe first pendulum hanger 13 and the weight 15 acts as a. pendulum element to" resist movement of sleeve 8' 'andto resist rotation of the drum- -4.

Hanger T3 is bifurcated at its lower end to receive the drum, said drum being fixed upon a shaft 16 that is" mounted upon anti friction bearings 1T-in the arms 13-h; off hanger 13; A contact arm- 18; fixed-to shaft I6, carries a spring l9 which-forces a'steei-hall E'O'outWa'rdIY'andintO contact" with theinner periphery of the rim '21 of a contact disk'fi. This disk is of non-conflnctive material such as fibre, and-upon the I inner--periphery of its rim itcarries arcuate contact strips a; a; h, b. The local pendulous action-oi the drum H tends to hold arm t8 stationary, while the contact disk turns with respect-to said arm as the plane tilts upwardh or downwardly in itslongitudinal plane. The 'said contact' d'iskisfiked'to the hanger 1'3 and 'sw ingsaboutthependulum held-shaft 16; The

-'-periphery of the-drum "I4 is graduated'from 0 to 1-80 degrees in both directions from its "zero point and when the plane is upon anevenkeel the -zeropoint-eoincides with a line 23 which constitutes an artificial horizon, said line bein formed'upon the-lower portion of disk land the scaieil upon'the periphery o'f-the drum bei-ng visible-through a sight opening 25 formed in disk H Sincethe drum tends to remain stationary nnder the action of pendulous weight,

the-"moveme-nt of-the l-irreit over scale '24- as the plane longitudinaily tilts; gives a degree by degree reading *of the extent of said tilting through P80" in either an up ordown direction. Iii-like-manner-the-m0vement-of1pointer '12 past itsdiski-II gives a degree' by degree'reading' of the lateral tiit" or bankpf" theplah'e in" either 'direct i'on' through 180'"; I may, 'i'f'desired, color the periphery ofthe drum 14; makin-g'thearea at the zero-point whiie; the area'from a'bout'the 'zerot-o' 20' mark; white, from the 20 to 40 'degrew-marks; irel'lowmhe'areas from 4-0 to 'degree'marks; orange, and the areas beyondtha't, red." Kl'though'this is a matter of choice andis merely an aid in'fvisuaily indicating'to thepildt the-degree abnormality of the tilt.

3 In addition to the readings in degrees as heretofore described, I provide a group of lights intended to give a quick indication to the pilot of any departure from level flight and without re-.

quiring him to divert his attention from the controls, in times of emergency.

To this end I mount upon the base 5 a group of lights disposed in the general form of a cross, and comprising an up white light, a down white light, a left white light, a right white light, and an up red light and a down red light. These lights consist of incandescent bulbs, the sockets of which are carried by a metallic plate 30 which plate may be electrically grounded at 3|. A fixed fibre distributor disk 32 is secured to the rod '1 and presents at its front face a group of arcuate contact strips 0, c, d, d, which respectively have electric connection with the con:- tact strips a, a, b, I), through the medium of brushes 6 and conductors I. These brushes may lights will make sufficiently clear how these various lights are energized. A source of current, such as the battery B is connected at one side to any suitable point upon the mechanism, such for example as the bracket 6. The circuit to light 43, for example, would then be through bracket 6, rod 1, sleeve 8, hanger l3, shaft l6, contact arm l8, strip or segment a, one of the conductors f and brushes 2 to strip or segment 0', thence through conductor 42 to the center contact of light bulb 43, thence through the lamp socket of said bulb to the base and back to ground or other side of the battery at 3|. The brushes e for all of the fore andaft tilt indicating lights, namely 40, 43, 45 and 41 are insulated from hub 33 and consequently from each other. The

1 circuit for the lateral tilt or"bank lights would 1 be from bracket 6, rod 1, sleeve 8, hub 33, brush be and preferably are like the contact arm l8,

having a spring i9 and ball 20; This is a common mechanical expedient and needs no further de:

scription. These brushes are fixed in and move with a hub-like extensionSE of sleeve 8. Insofar as the strips 0, c, d, d are concerned, these function merely as current distributing means, the selected contact for these being made by arm l8 and associated parts. However, I also 'provide upon the face of the distributor disk 32 a pair of arcuate strips R and L, the strip B being connected by a conductor 34 with the right white light 35 and the strip L being connected by a conductor 36 with the left white light 31. The hub-like extension 33 of sleeve 3 carries a contact brush-33 which as long as the plane rides upon an even lateral keel, rests upon. a non conductive area X, between the strips R and L. However, upon banking in either direction, this brush will connect with the strips R or L and the corresponding light 35 or 31 will be lighted. This action will be brought about by movement of the strips R and L, with respect to the brush, rather than by movement of the brush with respect to the strips, because the action of the pendulum constituted by the hanger l3 and associated parts tends to hold the sleeve 8 and the brush 39 stationary, while the disk 32 tends to turn bodily with the'plane as the latter banks. It will be observed that the strips a, afloccupy only about each, therefore during. the first 45 of upward tilt, the up white light 40 will be lighted, the contact being from a, c and thence through conductor 45, to the center contact of light 40. Upon a downward tilt connection will be from a and its associated conductor 1, and brush e to distributor strip 0, thence through conductor 42 to the down white light 43. If the degree of upward tilt should be sufficiently steep to bring 12 into engagement with contact arm i8, then b will be connected to d and through d and conductor 44 with the upward light 45.

Ifthe degree of downward tilt should be sufiiciently great to bring b into engagement with,-

The brushes e are suitably insulated-from the hub-like extension 33 and thecontact strips 0, 0, cl, d, R and L, are providedupon the rear side of the distributor disk 32 with suitable bind- .ing posts for the attachment of the wires leading to the lights. It is thought that the tracings of a complete circuit to one of the up and down 39 (which is not insulated from hub 33) strip R or L, as the case may be, conductor 34 or 35 to the .lights 35 or 37 and thence through base plate 35 to ground or return lead 3|.

I Wish it to be understood that the electrical connections may be varied at will as long as they are such as to accomplish the foregoing objects. Also, that many other changes may be made in the details of construction without departure from my basic idea. As far asI am aware, I am the first-to provide an inclinometer comprising two pendulums one of which is carried bodily'by the other and the weight of which affects said other pendulum, one of said pendulums controlling indicating means for indicating the lateral tilt of a plane and the other of which controls indicating means for indicating the longitudinal tilt of the plane and each of these being operative through a total of 360 or 180. from normal in both directions. Also, I believe it to be novel with me to secure a fine indication by dials and pointers of the respective inclinations and a coarser indication as by lights, of the same. Note that the plane can turn completely over without disrupting the readings of the dials l0 and 24 and associated indicators.

Therefore, it is to be understood that the invention includes within its purview whatever changes fairly come within either the terms or the spirit of the appended claims.

Having described my invention, what I claim is:

1. In an inclinometer for registering both the longitudinal and lateral tilt of an airplane, a fixed shaft, means for supporting said shaft upon an airplane with its axis parallel to the longitudinal axis of the airplane, a sleeve mounted upon said shaft, said shaft being capable .of complete rotation in said sleeve through 360 degrees, a pendulum depending from said sleeve and. resisting movement of said sleeve under lateraltilting of the plane, a second pendulum mounted in the lower portion of the first named pendulum and about an axis disposed transversely of the plane, a graduated dial fixed to the said sleeve, a pointer carried by the shaft and coacting with said dial, graduations upon the second pendulum and an indicating element upon the first named dial coacting with the graduations upon the second pendulum.

2. A structure as recited in. claim 1, wherein the second named pendulum is in the form of a rotative drum having a weight in its lower portion.

3. A structure as recited in claim 1, wherein the second pendulum is mounted upon the shaft which constitutes its axis of rotation, said shaft being supported in the depending first-named pendulum, said second pendulum being capable of rotation through 360 about its axis.

4. A structure as recited in claim 1, wherein the first-named dial is provided with a sight opening through which the periphery of the second pendulum is visible, the indicating means of the second pendulum comprising a scale upon the periphery of said pendulum and wherein said second pendulum is in the form of a weighted circular drum.

THOMAS D. PENNINGTON.

REFERENCES CITED The following references are of record in the file of this patent:

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